Reliability-based geotechnical design : towards a unified theory

A review of theoretical probabilistic models devised over the last decade for geotechnical reliability-based design reveals that they generally follow the same form. That form can be used to develop a unified reliability-based design approach that includes the effects of spatial variability in the ground, site understanding, and the severity of failure consequences. This paper develops and describes the resulting unified model, along with recommendations regarding its use in practice. The approach can be used to directly provide required resistance factors for use in an LRFD format.